A conventional supercharging pressure control device of this type of construction is disclosed in German Offenlegungsschrift No. 2,928,902. The control device in the control conduit is connected downstream of the throttle valve and to the second chamber of the regulating unit. The control device consists of a check valve which, depending on the desired operating mode, opens when a vacuum prevails downstream of the throttle valve or is blockable in the closed position. With this supercharging pressure control, the closing force acting on the bypass valve, when the check valve is not blocked, is reduced only if the pressure in the intake manifold lies below atmospheric pressure. A marked reduction of the closing force to avoid unnecessary buildup of supercharging pressure upstream of the throttle valve occurs only in the lower partial load range wherein no high supercharging pressures and exhaust pressures are reached even with customary supercharging pressure regulation. Therefore, the advantage attainable with this supercharging pressure control is relatively minor.